The Pediatric Rheumatology Tissue Repository (PRTR) will assist local and national investigators in collecting, processing, storage and using biospecimens for rheumatic diseases-related studies to enable translational research to elucidate the causes of arthritis and other rheumatic diseases in children. The principal functions of this core are: ? To collect, process and maintain biological specimens from patients with pediatric rheumatological and related musculoskeletal conditions as well as from relevant control populations for research purposes. Samples collected include blood, urine, synovial fluid, synovial tissue, hair and saliva. Products derived from these collections are suitable for genetic, genomic, proteomic, immunologic function and biomarker studies. ? To create a ?new onset disease? (NOD) sample resource to include samples from treatment naive patients presenting with a pediatric rheumatic disease at Cincinnati Children's Hospital Medical Center. This resource will streamline recruitment in the clinic and has potential to attract new investigators and new studies. ? To optimize the availability and potential for use of sample collections. Established practices of the PRTR for sample collection, processing, shipping and the training of clinical site personnel both locally and in the CARRA community ensure that the scope of specimens needed for translational research projects are available to meet current and future study needs. When possible collections are standardized to be consistent with other national and international efforts. High quality samples in appropriate formats will be provided for investigators conducting IRB-approved basic and translational studies in pediatric rheumatologic disease. Informatics solutions for sample storage documentation will allow accurate and use. The PRTR is a unique resource that is important to enabling definitive genomic and biological studies necessary to understand and define childhood rheumatic diseases.